2 String Quartets Opp.16 & 17 (pub.1863) (Op.17 may be RISM 452001998 of by-1858 (and see WorldCat links, it's the same work, but Op.16 is in A minor according to the ad in NZM 1863 p.182...), though the op.nos. listed for his 2 quartets there are 97 (in D) and 98 (in E♭) - perhaps there are many more qts in ms). There may be two published qts no.1, opp.12 & 16.)

String quintet in E minor, Op.5 (a library estimates ca.1820, but "Quintetti" by Aimon are mentioned in Le Moniteur judiciaire de Lyon in 1809 so ca.1809 seems closer for first publication date, if the same quintet.)

While works first published before 1968 are PD in Canada, the works of this composer are copyright in the EU.Only works published before 1923 are PD in the USA.
Also known as Alexander Albrecht.
Much information including list of manuscripts, etc. @ Albrechtforum.eu. Works mostly PD-CA at present if that?

1740: Alfred, opera in 3 acts, originally written as a masque to celebrate the accession of George II in 1740. Was later revised into an all sung oratorio in 1745 and then greatly expanded into its final version as an opera in 1753. A score of the final version still survives

1751: Eight overtures in 8 parts, collection of overtures from various stage works by Arne including the overtures for Henry and Emma, Comus, and The Judgment of Paris. First used for a concert performance in 1751, the collection most recently published by J. Herbage in 1937

(also Léo Arnold; +pseudonym de Cazeteaux. Married sculptor Henry Arnold in 1903. Almost a dozen digitized works @ Gallica under Léo d'Autezac.) (Sorry, have no better estimate of dates, am breaking own rules here...)

While works first published before 1968 are PD in Canada, the works of this composer are copyright in the EU.Only works published before 1923 are PD in the USA.
(One of two composers by that name. It's not certain the following work, mentioned in HMB, is from this composer rather than the other, though their birth and death dates are nearly the same fwiw- still, identification would be good...)

Totentanz, Op.29 for mixed chorus and large orchestra. Reduction by W. Walloth published 1925 by Tischer & Jagenberg.

Symphony in E minor (1906? at the latest) (see Verwaltungs- Rechenscahft Mainz) (describes the orchestra's financial records, season, says Kapellmeister Hermann Behr conducted the orchestra in his own symphony in E minor, - this may be an earlier performance, perhaps also a different orchestra, than a 1907 one described in another contemporary journal.)

1875 seems an unlikely birthdate unless he was a considerable prodigy, whatever Riethmuller's Busoni in Berlin says? :)... Behr was already published by 1888 (see Hofmeister's Monatsbericht (1888), p.422 for example) and up to Op.8 by 1890 (Hofmeister's Monatsbericht (1890), p.322 - 10 (Opp.9&10 were also published in 1890, see p.341) published works with assigned opus numbers by age 15, assuming these are all the same person and age 15 is accurate. Where is "1875" from anyway (there are many "Hermann Behr"s about in the records?)... It reads more like a flourishing date that got misread as a birthdate along the way by someone?... - E.S. (note: Op.8, Der Frühling : zehn characteristische Variationen, can be downloaded here, so one can at least create the category and get started.

Evidently, Universal Edition committed copyfraud when it published its edition copyright 1924 (renewed by Helene Berg in 1952). This work was first published in 1920 by Schlessinger in Berlin. Consequently it is now PD in the US, in the EU and in Canada. The 1924 Universal Edition is posted on IMSLP. However, Americans may be reluctant to touch this work unless the Schlessinger Edition is also posted on IMSLP with its 1920 copyright date clearly displayed – to provide irrefutable documentation that the work is now PD.

Symphony in D, Op.42 (autograph by 1820? at Berlin State Library; pub.1843 Hofmeister)

Piano Concerto in C, Op.34 (pub. 1841 in solo reduction by Hofmeister, like symphony also in complete edition. Parts at SBB.)

String Quartet in G (the most complete - apparently entirely- of the "8 quartets" for strings or flute and strings in manuscript at SBB. The quartets in F major and G minor may be a bit sketchy, the others apparently are partially fragmentary)

Violin Sonata No.3 in D (1881, A. O'Kelly et Naus) (also: 3 violin sonatas published by O'Kelly probably around 1881, the D minor not included - in B-flat, in F-sharp minor, in D major. So these are perhaps sonatas 2-4. Unless the D minor is by Jean-Maurice Bourges or similar?)

Under copyright worldwide, apart from earlier works (published before 1923) which are PD in the USA.No posting without written permission from the copyright owner.Public Domain Works (USA only)Six early orchestral works, published by Breitkopf & Härtel (B&H), London, 1914:

For valour, concert overture, op.7 (1904–06)

English suite no.1, op.12 (1906)

Fantastic Variations on an old Rhyme (1907–09/12)

Festal Dance, (1908–09)

In memoriam, symphonic poem (1910)

Doctor Merryheart, comedy overture no.1 (1911–12)

Other works:

The Tigers (1917–29) VS, Cranz, pub.1932 and registered for copyright but not renewed

Shall I compare thee to a summer's day?, op.5 (1903/04), B&H, 1905

Three Songs for Contralto or Baritone, op.6 (?1904/05), B&H, 1913

Psalm 137, By the waters of Babylon, op.11 (1905/09), VS, B&H, 1914

Stars of a summer night, op.1 (1905), Novello, 1908

The vision of Cleopatra, cantata, op.15 (1907), VS Bosworth, 1908/09

Various songs (solo voice, and partsongs) published by J. Curwen & Son, J.&W. Chester, Enoch, OUP and Augener before 1923

While works first published before 1968 are PD in Canada, the works of this composer are copyright in the EU.Only works published before 1923 are PD in the USA.
Tête de Kenwark, Scène lyrique for Cello and Orchestra

Double Piano Concerto in A-flat minor also called Op. 88); also full score or complete version for three pianos (one for orchestra). (So far only two movements are present, and arranged only for two pianos.)

BuxWV 245 - 250 (in modern sheet music, not tablature) (if possible. 250 particularly given its possible relation to Bach's Goldberg set? - Schissel, who would find any representation- a recording, arrangement, tablature, of BuxWV 250 to be acceptable, so long as it was copyright-ok goes-without-etc. ...)